Split out foreground session tracking from the application code.

BUG=560466

Review-Url: https://codereview.chromium.org/2348583002
Cr-Commit-Position: refs/heads/master@{#419340}

chrome/android/java/src/org/chromium/chrome/browser/BrowserRestartActivity.java

@@ -19,7 +19,8 @@ import org.chromium.chrome.browser.util.IntentUtils;
 /**
  * Kills and (optionally) restarts the main Chrome process, then immediately kills itself.
  *
- * Starting this Activity should only be done by the {@link ChromeLifetimeController}, and requires
+ * Starting this Activity should only be done by the
+ * {@link org.chromium.chrome.browser.init.ChromeLifetimeController}, and requires
  * passing in the process ID (the Intent should have the value of Process#myPid() as an extra).
  *
  * This Activity runs on a separate process from the main Chrome browser and cannot see the main
@@ -27,14 +28,14 @@ import org.chromium.chrome.browser.util.IntentUtils;
  * AlarmManager, which requires a minimum alarm duration of 5 seconds: https://crbug.com/515919.
  */
 public class BrowserRestartActivity extends Activity {
-    static final String ACTION_START_WATCHDOG =
+    public static final String ACTION_START_WATCHDOG =
             "org.chromium.chrome.browser.BrowserRestartActivity.start_watchdog";
-    static final String ACTION_KILL_PROCESS =
+    public static final String ACTION_KILL_PROCESS =
             "org.chromium.chrome.browser.BrowserRestartActivity.kill_process";
 
-    static final String EXTRA_MAIN_PID =
+    public static final String EXTRA_MAIN_PID =
             "org.chromium.chrome.browser.BrowserRestartActivity.main_pid";
-    static final String EXTRA_RESTART =
+    public static final String EXTRA_RESTART =
             "org.chromium.chrome.browser.BrowserRestartActivity.restart";
 
     private static final String TAG = "BrowserRestartActivity";

chrome/android/java/src/org/chromium/chrome/browser/ChromeActivity.java

@@ -580,7 +580,7 @@ public abstract class ChromeActivity extends AsyncInitializationActivity
     public void onStartWithNative() {
         super.onStartWithNative();
         UpdateMenuItemHelper.getInstance().onStart();
-        getChromeApplication().onStartWithNative();
+        ChromeActivitySessionTracker.getInstance().onStartWithNative();
 
         if (GSAState.getInstance(this).isGsaAvailable()) {
             mGSAServiceClient = new GSAServiceClient(this);

chrome/android/java/src/org/chromium/chrome/browser/ChromeActivitySessionTracker.java

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.chrome.browser;
+
+import android.app.Activity;
+import android.content.SharedPreferences;
+import android.provider.Settings;
+
+import org.chromium.base.ApplicationState;
+import org.chromium.base.ApplicationStatus;
+import org.chromium.base.ApplicationStatus.ApplicationStateListener;
+import org.chromium.base.ContextUtils;
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.VisibleForTesting;
+import org.chromium.base.metrics.RecordHistogram;
+import org.chromium.chrome.browser.accessibility.FontSizePrefs;
+import org.chromium.chrome.browser.browsing_data.BrowsingDataType;
+import org.chromium.chrome.browser.browsing_data.TimePeriod;
+import org.chromium.chrome.browser.metrics.UmaUtils;
+import org.chromium.chrome.browser.metrics.VariationsSession;
+import org.chromium.chrome.browser.notifications.NotificationPlatformBridge;
+import org.chromium.chrome.browser.partnercustomizations.PartnerBrowserCustomizations;
+import org.chromium.chrome.browser.preferences.PrefServiceBridge;
+import org.chromium.chrome.browser.share.ShareHelper;
+import org.chromium.chrome.browser.tabmodel.TabModelSelector;
+import org.chromium.chrome.browser.util.FeatureUtilities;
+import org.chromium.content.browser.ChildProcessLauncher;
+
+import java.lang.ref.WeakReference;
+import java.util.Locale;
+
+/**
+ * Tracks the foreground session state for the Chrome activities.
+ */
+public class ChromeActivitySessionTracker {
+
+    private static final String PREF_LOCALE = "locale";
+
+    private static ChromeActivitySessionTracker sInstance;
+
+    private final PowerBroadcastReceiver mPowerBroadcastReceiver = new PowerBroadcastReceiver();
+
+    // Used to trigger variation changes (such as seed fetches) upon application foregrounding.
+    private VariationsSession mVariationsSession;
+
+    private ChromeApplication mApplication;
+    private boolean mIsInitialized;
+    private boolean mIsStarted;
+    private boolean mIsFinishedCachingNativeFlags;
+
+    /**
+     * @return The activity session tracker for Chrome.
+     */
+    public static ChromeActivitySessionTracker getInstance() {
+        ThreadUtils.assertOnUiThread();
+
+        if (sInstance == null) sInstance = new ChromeActivitySessionTracker();
+        return sInstance;
+    }
+
+    /**
+     * Constructor exposed for extensibility only.
+     * @see #getInstance()
+     */
+    protected ChromeActivitySessionTracker() {
+        mApplication = (ChromeApplication) ContextUtils.getApplicationContext();
+    }
+
+    /**
+     * Handle any initialization that occurs once native has been loaded.
+     */
+    public void initializeWithNative() {
+        ThreadUtils.assertOnUiThread();
+
+        if (mIsInitialized) return;
+        mIsInitialized = true;
+        assert !mIsStarted;
+
+        ApplicationStatus.registerApplicationStateListener(createApplicationStateListener());
+        mVariationsSession = mApplication.createVariationsSession();
+    }
+
+    /**
+     * Each top-level activity (those extending {@link ChromeActivity}) should call this during
+     * its onStart phase. When called for the first time, this marks the beginning of a foreground
+     * session and calls onForegroundSessionStart(). Subsequent calls are noops until
+     * onForegroundSessionEnd() is called, to handle changing top-level Chrome activities in one
+     * foreground session.
+     */
+    public void onStartWithNative() {
+        ThreadUtils.assertOnUiThread();
+
+        if (mIsStarted) return;
+        mIsStarted = true;
+
+        assert mIsInitialized;
+
+        onForegroundSessionStart();
+        cacheNativeFlags();
+    }
+
+    /**
+     * Called when a top-level Chrome activity (ChromeTabbedActivity, FullscreenActivity) is
+     * started in foreground. It will not be called again when other Chrome activities take over
+     * (see onStart()), that is, when correct activity calls startActivity() for another Chrome
+     * activity.
+     */
+    private void onForegroundSessionStart() {
+        UmaUtils.recordForegroundStartTime();
+        ChildProcessLauncher.onBroughtToForeground();
+        updatePasswordEchoState();
+        FontSizePrefs.getInstance(mApplication).onSystemFontScaleChanged();
+        updateAcceptLanguages();
+        mVariationsSession.start(mApplication);
+        mPowerBroadcastReceiver.onForegroundSessionStart();
+
+        // Track the ratio of Chrome startups that are caused by notification clicks.
+        // TODO(johnme): Add other reasons (and switch to recordEnumeratedHistogram).
+        RecordHistogram.recordBooleanHistogram(
+                "Startup.BringToForegroundReason",
+                NotificationPlatformBridge.wasNotificationRecentlyClicked());
+    }
+
+    /**
+     * Called when last of Chrome activities is stopped, ending the foreground session. This will
+     * not be called when a Chrome activity is stopped because another Chrome activity takes over.
+     * This is ensured by ActivityStatus, which switches to track new activity when its started and
+     * will not report the old one being stopped (see createStateListener() below).
+     */
+    private void onForegroundSessionEnd() {
+        if (!mIsStarted) return;
+        ChromeApplication.flushPersistentData();
+        mIsStarted = false;
+        mPowerBroadcastReceiver.onForegroundSessionEnd();
+
+        ChildProcessLauncher.onSentToBackground();
+        IntentHandler.clearPendingReferrer();
+        IntentHandler.clearPendingIncognitoUrl();
+
+        int totalTabCount = 0;
+        for (WeakReference<Activity> reference : ApplicationStatus.getRunningActivities()) {
+            Activity activity = reference.get();
+            if (activity instanceof ChromeActivity) {
+                TabModelSelector tabModelSelector =
+                        ((ChromeActivity) activity).getTabModelSelector();
+                if (tabModelSelector != null) {
+                    totalTabCount += tabModelSelector.getTotalTabCount();
+                }
+            }
+        }
+        RecordHistogram.recordCountHistogram(
+                "Tab.TotalTabCount.BeforeLeavingApp", totalTabCount);
+    }
+
+    private void onForegroundActivityDestroyed() {
+        if (ApplicationStatus.isEveryActivityDestroyed()) {
+            // These will all be re-initialized when a new Activity starts / upon next use.
+            PartnerBrowserCustomizations.destroy();
+            ShareHelper.clearSharedImages();
+        }
+    }
+
+    private ApplicationStateListener createApplicationStateListener() {
+        return new ApplicationStateListener() {
+            @Override
+            public void onApplicationStateChange(int newState) {
+                if (newState == ApplicationState.HAS_STOPPED_ACTIVITIES) {
+                    onForegroundSessionEnd();
+                } else if (newState == ApplicationState.HAS_DESTROYED_ACTIVITIES) {
+                    onForegroundActivityDestroyed();
+                }
+            }
+        };
+    }
+
+    /**
+     * Update the accept languages after changing Android locale setting. Doing so kills the
+     * Activities but it doesn't kill the Application, so this should be called in
+     * {@link #onStart} instead of {@link #initialize}.
+     */
+    private void updateAcceptLanguages() {
+        PrefServiceBridge instance = PrefServiceBridge.getInstance();
+        String localeString = Locale.getDefault().toString();  // ex) en_US, de_DE, zh_CN_#Hans
+        if (hasLocaleChanged(localeString)) {
+            instance.resetAcceptLanguages(localeString);
+            // Clear cache so that accept-languages change can be applied immediately.
+            // TODO(changwan): The underlying BrowsingDataRemover::Remove() is an asynchronous call.
+            // So cache-clearing may not be effective if URL rendering can happen before
+            // OnBrowsingDataRemoverDone() is called, in which case we may have to reload as well.
+            // Check if it can happen.
+            instance.clearBrowsingData(
+                    null, new int[]{ BrowsingDataType.CACHE }, TimePeriod.ALL_TIME);
+        }
+    }
+
+    private boolean hasLocaleChanged(String newLocale) {
+        String previousLocale = ContextUtils.getAppSharedPreferences().getString(
+                PREF_LOCALE, "");
+
+        if (!previousLocale.equals(newLocale)) {
+            SharedPreferences prefs = ContextUtils.getAppSharedPreferences();
+            SharedPreferences.Editor editor = prefs.edit();
+            editor.putString(PREF_LOCALE, newLocale);
+            editor.apply();
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Honor the Android system setting about showing the last character of a password for a short
+     * period of time.
+     */
+    private void updatePasswordEchoState() {
+        boolean systemEnabled = Settings.System.getInt(mApplication.getContentResolver(),
+                Settings.System.TEXT_SHOW_PASSWORD, 1) == 1;
+        if (PrefServiceBridge.getInstance().getPasswordEchoEnabled() == systemEnabled) return;
+
+        PrefServiceBridge.getInstance().setPasswordEchoEnabled(systemEnabled);
+    }
+
+    /**
+     * Caches flags that are needed by Activities that launch before the native library is loaded
+     * and stores them in SharedPreferences. Because this function is called during launch after the
+     * library has loaded, they won't affect the next launch until Chrome is restarted.
+     */
+    private void cacheNativeFlags() {
+        if (mIsFinishedCachingNativeFlags) return;
+        FeatureUtilities.cacheNativeFlags(mApplication);
+        mIsFinishedCachingNativeFlags = true;
+    }
+
+    /**
+     * @return The PowerBroadcastReceiver for the browser process.
+     */
+    @VisibleForTesting
+    public PowerBroadcastReceiver getPowerBroadcastReceiverForTesting() {
+        return mPowerBroadcastReceiver;
+    }
+}

chrome/android/java/src/org/chromium/chrome/browser/DeferredStartupHandler.java

@@ -194,7 +194,7 @@ public class DeferredStartupHandler {
 
                 PowerMonitor.create(mAppContext);
 
-                ShareHelper.clearSharedImages(mAppContext);
+                ShareHelper.clearSharedImages();
 
                 OfflinePageUtils.clearSharedOfflineFiles(mAppContext);
             }
@@ -231,9 +231,6 @@ public class DeferredStartupHandler {
         });
 
         ProcessInitializationHandler.getInstance().initializeDeferredStartupTasks();
-        // TODO(tedchoc): Remove this once all internal clients have moved to using
-        //                ProcessInitializationHandler.
-        application.initializeSharedClasses();
     }
 
     private void initAsyncDiskTask() {

chrome/android/java/src/org/chromium/chrome/browser/init/ChromeBrowserInitializer.java

@@ -249,7 +249,7 @@ public class ChromeBrowserInitializer {
         initQueue.add(new NativeInitTask() {
             @Override
             public void initFunction() {
-                mApplication.initializeProcess();
+                ProcessInitializationHandler.getInstance().initializePostNative();
             }
         });
 

chrome/android/java/src/org/chromium/chrome/browser/ChromeLifetimeController.java → chrome/android/java/src/org/chromium/chrome/browser/init/ChromeLifetimeController.java

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-package org.chromium.chrome.browser;
+package org.chromium.chrome.browser.init;
 
 import android.app.Activity;
 import android.content.Context;
@@ -12,6 +12,10 @@ import android.os.Process;
 import org.chromium.base.ActivityState;
 import org.chromium.base.ApplicationStatus;
 import org.chromium.base.ContextUtils;
+import org.chromium.base.ThreadUtils;
+import org.chromium.base.annotations.SuppressFBWarnings;
+import org.chromium.chrome.browser.ApplicationLifetime;
+import org.chromium.chrome.browser.BrowserRestartActivity;
 
 import java.lang.ref.WeakReference;
 
@@ -28,13 +32,24 @@ class ChromeLifetimeController implements ApplicationLifetime.Observer,
         ApplicationStatus.ActivityStateListener {
     private static final String TAG = "LifetimeController";
 
+    private static ChromeLifetimeController sInstance;
+
     private boolean mRestartChromeOnDestroy;
     private int mRemainingActivitiesCount = 0;
 
-    public ChromeLifetimeController() {
-        ApplicationLifetime.addObserver(this);
+    /**
+     * Initialize the ChromeLifetimeController;
+     */
+    @SuppressFBWarnings("LI_LAZY_INIT_UPDATE_STATIC")
+    public static void initialize() {
+        ThreadUtils.assertOnUiThread();
+        if (sInstance != null) return;
+        sInstance = new ChromeLifetimeController();
+        ApplicationLifetime.addObserver(sInstance);
     }
 
+    private ChromeLifetimeController() {}
+
     @Override
     public void onTerminate(boolean restart) {
         mRestartChromeOnDestroy = restart;

chrome/android/java/src/org/chromium/chrome/browser/init/ProcessInitializationHandler.java

@@ -15,9 +15,11 @@ import org.chromium.base.CommandLine;
 import org.chromium.base.ContextUtils;
 import org.chromium.base.Log;
 import org.chromium.base.ThreadUtils;
+import org.chromium.chrome.browser.ChromeActivitySessionTracker;
 import org.chromium.chrome.browser.ChromeApplication;
 import org.chromium.chrome.browser.DeferredStartupHandler;
 import org.chromium.chrome.browser.DevToolsServer;
+import org.chromium.chrome.browser.banners.AppBannerManager;
 import org.chromium.chrome.browser.download.DownloadController;
 import org.chromium.chrome.browser.download.DownloadManagerService;
 import org.chromium.chrome.browser.firstrun.ForcedSigninProcessor;
@@ -25,6 +27,8 @@ import org.chromium.chrome.browser.identity.UniqueIdentificationGeneratorFactory
 import org.chromium.chrome.browser.identity.UuidBasedUniqueIdentificationGenerator;
 import org.chromium.chrome.browser.invalidation.UniqueIdInvalidationClientNameGenerator;
 import org.chromium.chrome.browser.multiwindow.MultiWindowUtils;
+import org.chromium.chrome.browser.net.spdyproxy.DataReductionProxySettings;
+import org.chromium.chrome.browser.preferences.PrefServiceBridge;
 import org.chromium.chrome.browser.rlz.RevenueStats;
 import org.chromium.chrome.browser.services.AccountsChangedReceiver;
 import org.chromium.chrome.browser.services.GoogleServicesManager;
@@ -47,6 +51,7 @@ public class ProcessInitializationHandler {
     private static ProcessInitializationHandler sInstance;
 
     private boolean mInitializedPreNative;
+    private boolean mInitializedPostNative;
     private boolean mInitializedDeferredStartupTasks;
     private DevToolsServer mDevToolsServer;
 
@@ -149,6 +154,32 @@ public class ProcessInitializationHandler {
                         application, SESSIONS_UUID_PREF_KEY), false);
     }
 
+    /**
+     * Initializes any dependencies that must occur after the native library has been loaded.
+     */
+    public final void initializePostNative() {
+        ThreadUtils.assertOnUiThread();
+        if (mInitializedPostNative) return;
+        mInitializedPostNative = true;
+        handlePostNativeInitialization();
+    }
+
+    /**
+     * Performs the post native initialization.
+     */
+    protected void handlePostNativeInitialization() {
+        final ChromeApplication application =
+                (ChromeApplication) ContextUtils.getApplicationContext();
+
+        DataReductionProxySettings.reconcileDataReductionProxyEnabledState(application);
+        ChromeActivitySessionTracker.getInstance().initializeWithNative();
+        ChromeApplication.removeSessionCookies();
+        AppBannerManager.setAppDetailsDelegate(application.createAppDetailsDelegate());
+        ChromeLifetimeController.initialize();
+
+        PrefServiceBridge.getInstance().migratePreferences(application);
+    }
+
     /**
      * Initializes the deferred startup tasks that should only be triggered once per browser process
      * lifetime.

chrome/android/java/src/org/chromium/chrome/browser/share/ShareHelper.java

@@ -198,12 +198,13 @@ public class ShareHelper {
     /**
      * Clears all shared image files.
      */
-    public static void clearSharedImages(final Context context) {
+    public static void clearSharedImages() {
         new AsyncTask<Void, Void, Void>() {
             @Override
             protected Void doInBackground(Void... params) {
                 try {
-                    File imagePath = UiUtils.getDirectoryForImageCapture(context);
+                    File imagePath = UiUtils.getDirectoryForImageCapture(
+                            ContextUtils.getApplicationContext());
                     deleteShareImageFiles(new File(imagePath, SHARE_IMAGES_DIRECTORY_NAME));
                 } catch (IOException ie) {
                     // Ignore exception.

chrome/android/java_sources.gni

@@ -15,13 +15,13 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/BluetoothChooserDialog.java",
   "java/src/org/chromium/chrome/browser/BrowserRestartActivity.java",
   "java/src/org/chromium/chrome/browser/ChromeActivity.java",
+  "java/src/org/chromium/chrome/browser/ChromeActivitySessionTracker.java",
   "java/src/org/chromium/chrome/browser/ChromeApplication.java",
   "java/src/org/chromium/chrome/browser/ChromeBackgroundService.java",
   "java/src/org/chromium/chrome/browser/ChromeBackgroundServiceWaiter.java",
   "java/src/org/chromium/chrome/browser/ChromeBackupAgent.java",
   "java/src/org/chromium/chrome/browser/ChromeFeatureList.java",
   "java/src/org/chromium/chrome/browser/ChromeHttpAuthHandler.java",
-  "java/src/org/chromium/chrome/browser/ChromeLifetimeController.java",
   "java/src/org/chromium/chrome/browser/ChromeStrictMode.java",
   "java/src/org/chromium/chrome/browser/ChromeSwitches.java",
   "java/src/org/chromium/chrome/browser/ChromeTabbedActivity.java",
@@ -430,6 +430,7 @@ chrome_java_sources = [
   "java/src/org/chromium/chrome/browser/init/BrowserParts.java",
   "java/src/org/chromium/chrome/browser/init/ChromeActivityNativeDelegate.java",
   "java/src/org/chromium/chrome/browser/init/ChromeBrowserInitializer.java",
+  "java/src/org/chromium/chrome/browser/init/ChromeLifetimeController.java",
   "java/src/org/chromium/chrome/browser/init/EmptyBrowserParts.java",
   "java/src/org/chromium/chrome/browser/init/InvalidStartupDialog.java",
   "java/src/org/chromium/chrome/browser/init/NativeInitializationController.java",

chrome/android/javatests/src/org/chromium/chrome/browser/PowerBroadcastReceiverTest.java

@@ -8,6 +8,7 @@ import android.content.Context;
 import android.content.Intent;
 import android.test.suitebuilder.annotation.MediumTest;
 
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.Feature;
 import org.chromium.base.test.util.FlakyTest;
 import org.chromium.base.test.util.RetryOnFailure;
@@ -15,6 +16,8 @@ import org.chromium.chrome.test.ChromeTabbedActivityTestBase;
 import org.chromium.chrome.test.util.ApplicationTestUtils;
 import org.chromium.content.browser.test.util.CallbackHelper;
 
+import java.util.concurrent.Callable;
+
 /**
  * Tests for the PowerBroadcastReceiver.
  */
@@ -84,8 +87,13 @@ public class PowerBroadcastReceiverTest extends ChromeTabbedActivityTestBase {
     public void setUp() throws Exception {
         super.setUp();
 
-        ChromeApplication application = (ChromeApplication) getActivity().getApplication();
-        mReceiver = application.getPowerBroadcastReceiver();
+        mReceiver = ThreadUtils.runOnUiThreadBlocking(new Callable<PowerBroadcastReceiver>() {
+            @Override
+            public PowerBroadcastReceiver call() throws Exception {
+                return ChromeActivitySessionTracker.getInstance()
+                        .getPowerBroadcastReceiverForTesting();
+            }
+        });
 
         // Set up our mock runnable.
         mRunnable = new MockServiceRunnable();